The invention relates to telecommunications networks, and more particularly to advanced architectures for the description of telecommunication services.
The feature-interaction problem arises from the incremental, feature-by-feature, extension of telecommunications system functionality. As new features such as call forwarding, call waiting, or three-way calling have been added to telecommunication systems, it has become increasingly difficult to manage the behavioral complexity of the features and their interactions. Redesign of old features to fit smoothly with the new features is scarcely ever a practical option. Eventually, the resulting complexity damages the quality and productivity of all phases of telecommunication software development.
In the U.S. Pat. No. 6,160,883 xe2x80x9cTelecommunication System and Method,xe2x80x9d filed on Mar. 4, 1998, which is incorporated by reference herein, the inventors introduced an architecture for managing the feature-interaction problem. The inventors presented a virtual architecture for telecommunication systems, which they called distributed feature composition (DFC), in which a feature corresponds to a component type; each telephone call is handled by building a configuration of instances of these components, according to the features to be applied to that particular call. The feature component instances communicate by featureless internal calls that are connected by the underlying architectural substrate. A new feature is specified by describing its corresponding component type (or occasionally, two component types) and the rules for including the component instances into configurations. In the pending utility applications, xe2x80x9cRouting Extensions For Telecommunications Network System And Method,xe2x80x9d Ser. No. 09/644,128, filed Aug. 23, 2000, and xe2x80x9cProtocol Extensions For Telecommunications Network Systems and Method,xe2x80x9d Ser. No. 09/644,461, filed Aug. 23, 2000, which are incorporated by reference herein, the inventors enhanced and modified DFC to accommodate open telecommunication systems, mobile telecommunication users, multimedia telecommunication services, unified messaging, and other aspects of modern telecommunication systems and services.
In distributed feature systems like DFC, all feature logic, including the feature logic that controls media switching and processing, is distributed across a dynamic assembly of feature boxes for purposes of modularity. Media switching and processing, however, pose a problem. It is difficult to implement directly at the feature box the media switching and processing mandated by each feature box, for at least two reasons: (1) the media would often be traveling by long, inefficient paths, and (2) media transport would be far too fragmented. Accordingly, there is a need in the prior art for a distributed feature system that avoids tightly coupling the signaling and media processing.
It is an object of the present invention to provide a general-purpose media layer for a distributed feature system. It is an object of the present invention that the media aspects of a feature not compromise feature modularityxe2x80x94and be as distributable as the signaling aspects of the feature. Resource configurations, allocation strategies, and optimizations will evolve continually over time. It is advantageous for such resource changes to not require changes to features already installed in the networkxe2x80x94not even recompilations. It is an object of the present invention that inter-node bandwidth be utilized efficiently. The post-dial setup delay for a customer xe2x80x9ccallxe2x80x9d should be minimized. It is an object of the present invention that different media be synchronized within reasonable tolerances. It is an object of the present invention that fault tolerance, providing a level of reliability suitable for telecommunications, cover both signaling and media layers.
In accordance with an embodiment of the present invention, a distributed feature system environment is disclosed in which paths carrying media, e.g. voice or text, are fully separated from signaling paths. A plurality of media processing modules are utilized to establish media channels separate from signaling channels and wherein each media processing module is assigned to one or more feature modules in the distributed feature system. In a preferred embodiment of the present invention, each media processing module further comprises interfaces to feature modules of the distributed feature system and to other media processing modules and an engine which models processing connections of its assigned feature components. The separation of the media and signaling layers may be optimized by allowing certain feature modules to behave transparently with respect to a media channel.
These and other aspects and advantages of the invention will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings.